The buying spree continued after the turn of the century as price tags in the area approached seven figures.

It bought another house in Hambledon Road for $850,000 in 2001, before buying the one next door for $1.4 million two years later.

In 2007, the college splashed more than $5 million on three other properties in the street.

Across the road, the college bought 6 Hambledon Road in 2007 for $1.85 million. Photo: domain.com.au

Prior to last month’s auction, the school’s most recent purchase was a $2 million house in 2015.

It also owns all of the properties along Morrison Street, which has formed part of the school campus for many years.

Houses in Morrison Street are used for bagpipe lessons, media studies, administration and archiving. But the school would not comment on what purpose their 17 other properties served.

The school campus sits on 27 hectares of land in Hawthorn. Photo: Michael Clayton-Jones

In a statement, the school said it began buying neighbouring property after losing chunks of the school grounds to the state government for Citylink.

“On three occasions since the 1960s, the government has compulsorily acquired land from the school to construct the [south-eastern] freeway and enable its subsequent widening into the Citylink tollway,” a spokesperson said.

“Bound otherwise by the tollway, Yarra River and Glenferrie Road, the school has a long term strategy to re-establish grounds lost to the tollway by acquiring land to the north.”